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Le larynx assure de multiples fonctions de régulateur du flux respiratoire, de protection des voies aériennes inférieures et de phonation chez l'adulte. Chez le foetus et le nouveau-né, il a un rôle indispensable dans la croissance pulmonaire foetale et, à la naissance, dans l'établissement d'une ventilation aérienne adéquate. L'implication du larynx au cours des apnées centrales est de découverte plus récente. En effet, il a été montré que le muscle adducteur des cordes vocales (activité électromyographique (EMG) du muscle thyroaryténoïdien (TA)), était continuellement actif au cours des apnées centrales induites et spontanées de l'agneau. Cette activité électromyographique est contemporaine de la fermeture complète et étanche des cordes vocales, et permet le maintien d'un volume pulmonaire élevé pendant l'apnée. Les conséquences physiologiques de cette fermeture active de la glotte restent à préciser. Par ailleurs, malgré son importance, la coordination de l'activité musculaire laryngée au cours des déglutitions avec le cycle respiratoire a été incomplètement étudiée chez le mammifère nouveau-né. Les buts de ce travail étaient (1) de caractériser le rôle bénéfique de la fermeture glottique sur l'oxygénation au cours d'apnées centrales spontanées chez des agneaux prématurés, (2) de préciser l'influence des stades de conscience sur la fréquence des déglutitions non-nutritives et sur leur coordination avec le cycle respiratoire. Nous avons étudié (1) la pente de désaturation en oxygène au cours d'apnées spontanées chez quatre agneaux prématurés, en comparant lesapnées où le volume pulmonaire était maintenu (orifice de trachéotomie fermé) avec celles où il ne l'était pas (orifice de trachéotomie ouvert), (2) la fréquence des déglutitions non nutritives isolées et en bouffée, de même que leur coordination avec le cycle respiratoire, et leur association avec les apnées spontanées chez six agneaux à terme et six agneaux prématurés"--Résumé abrégé par UMI.

In the UK, there are up to 3,000 cancer patients who have undergone total laryngectomy and use voice prostheses (VPs), for speech rehabilitation. VPs are inserted between the eosphagus and trachea to provide a 'voice' but, as with other semi-in-dwelling devices, such as nasal and gastric tubes, they invariably fail due to occlusion by microbial biofilms. The requirement for frequent replacement is financially costly to the NHS and impacts patient well-being. Replacement frequency varies by patient, from 7 weeks to 6 months but the reasons for this variation are not clearly understood. By designing and implementing a study of microbial colonisation of VPs and oral rinse samples submitted by 14 Speech and Voice Clinic patients over 13 months, this study explored whether specific microbes or patient factors, including the use of antacids, antibiotics and nystatin, along with denture-use, were potential predictors of device longevity. Focussing on the role of the commonly isolated fungi, we sought to understand the role of diet or the presence of the bacterium, S. aureus, in biomass accumulation. We also asked whether biofilm regulation pathways are shared across the fungi and could constitute a potential target for therapeutics. Microbial isolation from 66 VPs showed the predominant species as described in previous studies, but each participant had a unique profile which persisted over time, with half of the microbes originating from the oral flora. Clinic-based participants experienced fewer problems, primarily due to the device type used, and carried fewer species of Gram negative bacteria than the long term users. Statistical analysis showed that patient medication influences biofilm composition and dietary sugars differentially affect biomass formation. In vitro experiments showed that the ability to treat Candida biofilms with nystatin was improved in the presence of S. aureus. Expression analysis showed that regulation of biofilms in C. parapsilosis was the closest to that of C. albicans but that the extent of protein homology to C. albicans regulators was not a predictor of expression levels. It is therefore unlikely that a single therapeutic could be developed to target biofilm gene regulation. This work provides new insights into the complexity of biofilm formation in voice prosthesis users but reveals associations between microbes, diet, prosthesis type and medications that might be used to advise patients and help to reduce the stress and cost of frequent device failure and replacement.

During phonation, the vocal folds collision during the glottal closure is considered to be a risk factor for pathological development. This thesis is aimed at designing a dependable finite element analysis (FEA) model of the vocal folds for frequency and dynamic analysis and for calculating the impact stress between the vocal folds during glottal closure. A three-dimensional model with irregular geometry and a layered structure was designed. The measured viscoelastic properties of the vocal-fold mucosa and the transverse isotropic elastic properties of the vocal fold muscle are applied to the model. The boundary conditions are assumed to be fixed on lateral, anterior and posterior surfaces based on anatomical structure analysis. This model is symmetrical about the right and left vocal folds.The frequency and dynamic characters are presented using the software ABAQUS. The FEA model is validated by both experimental modal analysis (EMA) model results and in-vivo experimental results from the literature.In the vibration analysis, the eigenfrequency and eigenmode of the FEA model are determined. The model results compare well with the experiments performed on a silicone vocal fold model. The eigenmodes show the vibration direction at different excitation frequencies. In the closure process, the closure and collision dynamic results are obtained. The results show that: (1) the closure process is independent of the subglottal pressure; (2) the glottal opening amplitude and closing velocity vary approximately linear with the subglottal pressure; (3) the maximum impact stress occurs on the mid area of the inferior surfaces; (4) the impact stress is approximately linear with the subglottal pressure; and (5) the impact stress will cause vocal fold tissue damage when the subglottal pressure is over 800 Pa.It is anticipated that the model will help to identify voice disorders such as vocal-fold paralysis and vocal-fold nodules.

Thesis (M.S.)--Brigham Young University. Dept. of Audiology and Speech-Language Pathology, 2006. / Includes bibliographical references (p. 79-84).

Referat: Bei der folgenden Arbeit handelt es sich um eine retrospektive Untersuchung der im Zeitraum von 1993 bis 2009 an der Klinik für Hals-Nasen-Ohrenheilkunde (HNO) der Universität Leipzig behandelten Larynx- und Hypopharynxkarzinome. Die Arbeit hatte zum Ziel, die Prävalenz, Risikofaktoren und Therapieergebnisse des fortgeschrittenen Larynx- und Hypopharynxkarzinoms im Spiegel geänderter Therapiestandards im genannten Untersuchungszeitraum zu analysieren. Im Vordergrund steht der ab 2004 eingeleitete Paradigmenwechsel in der adjuvanten Therapie dieser Tumoren aufgrund einer geänderten Studien- bzw. Datenlage. Inhaltlich handelt es sich um die evidenzbasierte Einführung multimodaler adjuvanter Konzepte, die sich durch die zusätzliche Applikation der Chemotherapie (Cisplatin/5-Fluorouracil) als simultaner Partner zur adjuvanten Strahlentherapie in definierten Risikosituationen auszeichnet. Die Arbeit untersucht die definitiven Therapieänderungen und einhergehenden Effektivitätsunterschiede im Untersuchungszeitraum. Hierbei blieben die Prävalenz der Larynx- und Hypopharynxkarzinome sowie der Konsum von Tabak und Alkohol, die als wesentliche Risikofaktoren gewertet werden, neben unwesentlichen Schwankungen über die genannten Jahre unverändert. Erwartungsgemäß zeigte sich eine Zunahme der adjuvanten platinbasierten Radiochemotherapie bei unverändert primär operativer Indikation, jedoch geänderter Risikoprofile (knappe bzw. tumorinfiltrierte Randschnitte [R1, R0 < 5mm] und kapseldurchbrechende Halslymphknotenmetastasen [ECS]) und der primären platinbasierten Radiochemotherapie bei nicht sinnvoll resektablen Tumoren. Diese Entwicklung führte insbesondere bei den fortgeschrittenen Larynx- und Hypopharynxkarzinomen zu einer signifikanten Verbesserung der Überlebensraten ab dem Jahr 2004. Dieser Zusammenhang konnte in einer multivariaten Betrachtung überzeugend herausgearbeitet werden und belegt die positiven Effekte einer systematischen Standardisierung von onkologischen Konzepten auf dem Boden sich ändernder Evidenz.

During phonation, the vocal folds collision during the glottal closure is considered to be a risk factor for pathological development. This thesis is aimed at designing a dependable finite element analysis (FEA) model of the vocal folds for frequency and dynamic analysis and for calculating the impact stress between the vocal folds during glottal closure. A three-dimensional model with irregular geometry and a layered structure was designed. The measured viscoelastic properties of the vocal-fold mucosa and the transverse isotropic elastic properties of the vocal fold muscle are applied to the model. The boundary conditions are assumed to be fixed on lateral, anterior and posterior surfaces based on anatomical structure analysis. This model is symmetrical about the right and left vocal folds.The frequency and dynamic characters are presented using the software ABAQUS. The FEA model is validated by both experimental modal analysis (EMA) model results and in-vivo experimental results from the literature.In the vibration analysis, the eigenfrequency and eigenmode of the FEA model are determined. The model results compare well with the experiments performed on a silicone vocal fold model. The eigenmodes show the vibration direction at different excitation frequencies. In the closure process, the closure and collision dynamic results are obtained. The results show that: (1) the closure process is independent of the subglottal pressure; (2) the glottal opening amplitude and closing velocity vary approximately linear with the subglottal pressure; (3) the maximum impact stress occurs on the mid area of the inferior surfaces; (4) the impact stress is approximately linear with the subglottal pressure; and (5) the impact stress will cause vocal fold tissue damage when the subglottal pressure is over 800 Pa.It is anticipated that the model will help to identify voice disorders such as vocal-fold paralysis and vocal-fold nodules.

Thesis (B.Sc)--University of Hong Kong, 2005. / "A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2005." Also available in print.

Thesis (B.Sc)--University of Hong Kong, 2005. / "A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2005." Also available in print.

Thesis (B.Sc)--University of Hong Kong, 2002. / "A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, May 10, 2002." Also available in print.